Meaning
Efficiency metric measures the percentage of electronic components that are lost or damaged during the automated surface mount assembly process. The surface mount scrap rate accounts for components dropped by pick-and-place vacuum nozzles, misaligned during feeding, or damaged in the reflow oven. This percentage applies to printed circuit board assembly lines and excludes finished product testing failures.
Production Loss
High assembly speeds increase the risk of components being dropped by robot nozzles during pick-and-place operations. The surface mount scrap rate is calculated by dividing the number of wasted components by the total number of parts loaded onto the machine feeders. This percentage must be kept low to prevent the waste of expensive semiconductor chips on high-volume runs.
Managers track this loss daily to identify specific component shapes or reel tapes that are prone to feeding failures, allowing them to adjust machine parameters before starting a new run.
Solder Quality
Component packaging can also cause issues if the tape and reel format is incompatible with the machine feeders. Worn-out feeder modules can result in poor alignment, which increases the scrap rate during the assembly process. This technical problem requires regular maintenance of the SMT machines to keep the feeder mechanisms running smoothly.
Sourcing Cost
Sourcing teams use this historical loss percentage to order excess components before starting a manufacturing run. If the line has an average scrap rate of one percent, the buyer must purchase an extra one percent of stock to avoid running out of parts. This safety margin prevents expensive line stoppages due to minor material losses during assembly.
